Wire-coiling die



Sept. 1, 1931.

S. WADSTEN WIRE COILING DIE Filed D60.

2 Sheets-Sheet l IRIIIIIIIIII ATTORNEY Sept. 1, 1931. s. wADsTEN WIRE COILING DIE Filed Dec. 28, 1929 2 Sheets-Sheet 2 INVENTOR 7271/ Wczvsrf/v ATTORNEY Patented Sept. l, 1931 NITED STATES PATENT OFFICE STEN WADSTEN, OF BLOOMFIELD, NEVI JERSEY, ASSIGNOR TO-WESTINGHOUSE LAMP COMPANY, A CORPORATION OF PENNSYLVANIA l WIRE-COILING- DIE Application filed December 28, 1929. Serial No. 417,185.

The present invention relates to an improvement in coil-winding machines such as shown and described in Patent No. 1,670,499 of May 22, 1928, to J. 1V. Elistedt and relates more particularly to coil-Windingv dies for use in such machines. Y

In the above-mentioned patent, a machine i-s shown for coiling fine hairlike Wire to helical formin the absence of a mandrel, and particularly for the production of such coiled Wire to serve as filaments for incandescent electric lamps. The machine shown com-4 prises mechanism for moving a Wire through a given path when tangentially engaged by a pair of oppositely-disposed driving rollers which drive the Wire endWise into a cavity die from which the Wire issues in the form of a continuous helix. Means are also provided for cutting the helix into sections of proper lengths to constitute filaments for incandes cent electric lamps. v Y

The die is so arranged that the cavity is positioned to receive the Wire from the driving rollers, the bottom of the cavity being inclined or grooved so that the Wire is bent into a succession of coils which pass over a lip or separator member at the edge of the cavity. The helix or successive turns of the coil Which issue from the die are consequently spaced a p given distance apart and a helix is, therefore, provided of a certain diameter and pitch depending upon the dimensions of the spacer member and the radius of curvature of the effective surface of the cavity as Well as the position of the die With respectto the driving rollers.

In the manufacture of coiled filamentary bodies which serve as electrical resistance elements when used as lamp filaments, it is essential to exercise extreme accuracy in the formation of the coils, since each ilament or coiled section must be made in accordance With specified dimensions so that each coiled section Vvvill have a lengt-h of Wire therein equal to the succeeding coiled section.

Furthermore, the diameter .of the coil as Well as the spacing or pitch of the turns of` the coil must be uniform. The dimensions of the diameter and the proportions of the coiled sections vary for lampsvof different Wattage and the `data relating to such Adimensions and proportions is known as the rating7 so that a coiled section for a given rating must be made in accordance With a predetermined set of dimensions. F or example, a filament for a Watt 115 volt lam must contain a length of Wire of 517 mm., it must have a diameter of .0108 of an inch and the coiled section must contain 398 turns per inch. The diameter of the wire also varies in filaments of different Wattage lamps and the diameter of the Wire of a coiled lament of a 60 Watt lamp is preferably .00187 of an inch. l

It Will be obvious that in order to produce a lamp lament and hold the coil formation to the required proportions and dimensions it is necessary to accurately form the coilwinding die and to provide accurately adjustable meansfor holding the said die in a given relation to the path of movement of the Wire thereto. In the above-mentioned patent a coil-Winding diey is shown and described as preferably consisting of an. eX- tremely hard material such as a diamond. `A

diamond die, although having indefinite' life, is dificult to produce and owing to variations in the properties of a diamond`,it is very often brittle to the extent that portions of the coil-Win-dinglip are broken of'rendering theV die inoperative for the `purpose intended. 1 y

As set forth in the said patent, the coil- Winding die may be constructed from hardened steel, but inasmuch as the' Wire passing over the die results in excessive Wear,

itis necessary to replace the steel die at shorter intervals than is necessary With a diamond die. i

Ordinarily the replacement of one die for another Would offer aL considerable disadvantage `since When applying a die into position for the Winding of a coiled filament, it is necessary to adjustthe diein several planes until the cavity is accurately located in'such position that the diameter and pitch ofthe coil producedl will be in accordance with the Vdata suppliedv for the rating of the particular lamp for which the filament is to be used.`

When. using a diamond die, the die remains in the machine for suoli a long period that the amount of labor and inconvenience involved in a change from one die to another is negligible. A. steel die, although easier to produce7 must be changed at comparatively short intervals and the advantage given by the facility accompanying the production of the die is lost by the time and labor involved in replacing the same.

An object of the present invention is, therefore, to provide a steel or other easily manufactured Fdie having a coil winding cavity so arranged as to expedite the disposi-tion of the cavity for a coil-winding operation.

Another object oi' the invention is to provid-e -a die having a plurality of coil-winrgling apertures adapted for substitution one Jfor the other.

Another object of the invention is to pro-- vide a coil-winding die having a cavity so formed as to be disposed in accordance with the pitch of the coil to be produced.

Other objects and advantages of the invent-ion will be more Jfully understood from the following description; l

The invent-ion may be practiced by providing a coil wound tightly upon a mandrel and withthe turns of the coil in contacting relation so as to make what is termed a closed coil. This. coil may lthen be used a primary embossing matrix and may be suitably supported so that a pair or" die blanks in the form of discs may be disposed with vtheir edges or peripheries in contact with opposite sides of the coil. The blanks may then be rotated in the presence of suiieient force to compress the blanks upon the embossing` matrix during a movement of the blanks over the matrix which movement may continue until an initial depression is obtained inv the blanks.

.Another or secondary embossing matrix may be provided by winding a wire upon a mandrel with the spaced relations ot the turns of the coil of a predetermined degree or pitch in accordance with the desired pitch to be obtained in the die produced and consequently in the coil produced by means of the die. Blanks with the initial depression therein may then be rolled over the secondary embossing matrix in the presence of a sut'- icient force to impressthe blanks with an impression of the properly spaced coil. The blanks may then be hardened'and employed as coil-winding elements, ordies in a mandrelless coil-winding machine.

Y The foregoing description briefly sets forth the general operation of practicing the present methochwhich operation will be more ullyunderstood by reference to theaccompanying drawings in which:

Fig. 1 is a side VelevationalviewV of aV primary4 embossing matrix showing die blanks in contactttherewith and partly in section;

Fig. 2 is aside elevational view of the secondary embossing matrix showing the die blanks in contact therewith partly in section Fig. 3 is a side view of a fxture for holding die blanks in position to be rolled over a matrix during the application oi' a compressive force;

Fig'. l is an end view of the fixture shown in Fig. 3;

Fig. 5 is a side view of a die blank partly broken away to show the depressions in the periphery thereof;

Fig. 6 is a side view of the die blank having a portion cut away to facilitate the use ot one ot' the cavities or depressions of the blank;

. Fig. 7 is an enlarged view oi" a portion oi the die blank shown in Fig. 6 looking in the direction of the arrow X;

Fig. 8 is an edge view oi' a die blank after the depressions have been made therein and with a portion cut away;

lfig. 9 is a view of a die blank similar to that shown in Fig. 8 but having concave chamfered edges to accomodate the proper disposition of the blank in relation to a coilwindingmachine;

Fig. 10 shows a die positioned in operativo relation to a coil-winding machine .tbr the pertormance of a coil-winding operation; and

winding elements sho\ in in Fig. 10.

The present invention may be practiced by providing a pair of disc-like members lll and 11. These members may be provided with suitable peripheral grooves 12 and may be provided with beveled edges. The blanks may be of any suitable material such as relatively soft steel capable otbeing hardened.

A suitable primary matrix may be provided by winding a wire 13 upon a mandrel 111 with the lturns of the wire vin Contact so as to produce a closed coil 13. The ends 15 and 16 of the coil may be held by clamps 17 and 18 of any suitable character.

The mandrel 14 may be 'supported in a holder (not shown) and the blanks 10 and 11 may be disposed so that the grooves 12 engage with the opposite sides of the coil 13. rfworblank rollers or discs are employed in order to balance the pressure and prevent a sagging of the mandrel during the operation oi impressing the coil into the peripheries ot the blanks. For the purpose of applying force to the rollers during their movement over the coil 13, a fixture 19 may be provided consisting of a bracket 20 having an extension 21 from which a spindle or shaft 22 may extend to receive the blank 10. The blank may be held rotatably in position by an end 23. The blank 11 may be mounted on a spindle 9A extendingfrom a slide plate 25 suitably held between guides 26 and 27 secured to the iixture 19. The blanks 10 and 11 may be disposed in the same plane with Fig. 11 is top view ot' the die and coilist' [ifi

the grooves 12 of their peripheries arranged to receive the coiled wire 13.

When the said blanks are in position at opposite sides ofthe coil 13 a relative movement may be efi'ected between the coil and the blanks to cause a rotation of the blanks, and at the same time a force may be applied by turning a set-screw 28 extending through a base portion 29 of the fixture 19. The setscrew may be provided with a collar 30 to prevent endwise movement of the set-screw, and a threaded end 31 of the set-screw may enter a threaded aperture 32 in the slide 25 so that a rotation of the set-screw will cause the slide andconsequently the roller 11 to be moved to or from the roller 10, and thus the wire between the rollers may be compressed.

It is obvious that it is immaterial whether the fixture 19 is moved to cause a rotation of the rollers over the coil or whether the coil itself is reciprocated along its longitudinal axis. It has been found, however, preferable to mount the mandrel 14 supporting` the coil, in a lathe.

In practicing the invention, it has been found that manufacturing conditions are met by performing the method in the following successive operations. For example, a die for a 10 watt lamp may be made in accordance with data calling for a coil of .004 of an inch outside diameter having 1000 turns per inch. formed from a wire of .0006 of an inch in diameter. In order to make a die for a coil in accordance with the above-mentioned data, a tungsten wire of .00099 of an inchy diameter is used and wound on a steel mandrel of .0025 of an inch diameter so as to produce a coiled section with the turns of the coil in contact or what may be termed a closed coil. In producing the said closed coil, a mandrel type coiling machine is employed which is said to obtain 1000 turns per inch and the coiled sections produced should be about 3 feet in length. This coiled section is what is termed the primary embossing matrix. This embossing matrix 13 may then be held in position so that the die blanks 10 and 11 may be rolled thereover.

After each movement of the die blanks over the coil, the pressure between the coil and die blanks may be increased until an appreciable depression is produced in the blanks. After the completion of the operation of forming the die blanks. another coiled section is produced with a left-hand Winding and made in accordance with the proper coil-winding data. This second wound coil is spaced to the proper pitch and is termed the secondary matrix 33 asshown in Fig. 2.

The operation of rolling the blanks over the ,coil is performed in the same manner as above described for the initial depression taken from the primary .iatrix 13. The blanks may then be hardened and heattreated and the edges 34 and 35 of the blanks adjacent the'coil-Winding periphery may be groundlto provide clearance for'Wiredriving rollers 36 and 37'which contact with ,a wire 38 to beldriven into a die to produce a manf drelless coiled section 39. v Y f After the operation of formingthe depressions in they blanks has been performed, the blank is provided with a pluralityof coilwinding depressions 40, each of the blanks being similar and constituting a die-member 41 as shown in Fig. 5. The Vdie-member 41 may be employed yas a wire-bending element by utilizing one of the cavities 40 and a ridge 42 as a spacer member for the coils. By'holding the die-member-41 in position so that the wire 38 is driven against the cavity 40, `the coils will issue from the cavity and be spaced by reason of the ridge or lip 42. It has been found preferable, however, to cut away a portion of the dieemember as shown in Fig. 6, leaving the lip or ridge 42 with a shorter face 43 so that the coils vvhen'issuing from the depression 40 'will more readily escape fron'rthe die. f

It will be evident that by reason of the plurality of depressions provided in the diemember, each depression constitutes a die- Vbending surface and upon the failure of one as by wearing or breaking, another may be utilized by either' moving the die-member 41 or by grinding away the face 43. Itfwill be further appreciated that inasmuch as the depressions are formed exactly in Laccordance with the pitchof the mandrelless coil to be produced that a more accurate and uniform winding insofar as diameter and pitch are concerned will be produced.`

The dife-member 41 may be `used inthe form as shown in Fig. 8 lin which theedges of the vdie vhave a tapered or chamferedface 44. The die-member, however, may be made moreeffective for the coil-winding operation by grinding the edges 34 and 35 to-a'radius or concavely as shown in Figs. 9, 10 and ll so thatthe die-member may be moved in close relation to the tangential point of thel driving rollers 36 and 37 which constitute part of the coil-winding machine set forth in the above-mentioned patent.

It is obvious that the die-blank may be made of any suitable material, as for example, soft steel which may be hardened as above set forth; or the said blank may be of a soft material which will harden after the pressing operation, as, for example, a soft heated material which hardens upon cooling. Furthermore, the blank need not be a disc, but may be in the form of a bar or block which may be pressed into contact with the coil-forming matrix.

The present inventionk therefore provides a coil-winding die which may be produced in a convenient and expeditious manner at comparatively low cost. The die produced has long life by reason of the multiplicity of coil-Winding surfaces and is easily adjustable to substitute one surface for another.

Although a preferred embodiment of the invention is shown and described herein, it is to be understood that variations and modiications may be made therein Without departing from the spirit and scope of the invention as set forth in the appended claims.

What is claimed is:

Vl. A coil-Winding diehaving an arcuate edge and with the perimeter thereof provided With coil-Winding depressions of substantially the same pitch as the coil to be produced.

2. A coil-winding die comprising a body with an arcuate edge having aplurality of substantially transverse depressions of substantially the same pitch as the coil to be produced.-

3. A coil-Winding die comprising a member having an arcuate edge Witha plurality of substantially transverse depressions arranged in spaced relation and with substantially the same pitch as a coil to be produced.

4. A coil-Winding die comprising a blank having a plurality of coil-Winding depressions of substantially the same pitch as the coil to be produced, said blank having a portion thereof removed to provide a coilseparating edge adjacent to one of said depressions, Y

5. A coil-Winding die comprising a disc having acurved perimeter With a plurality of coil-Winding depressions formed therein.

6. A coil-Winding die comprising a circu lar disc having a peripheral groove and a plurality ofdepressions in said groove arranged in given spaced relation in accordance with the spacing of a coil of a given pitch.

In testimony whereof, I have hereunto subscribed my name this 14th day of December,

STEN WADSTEN. 

